Dell vostro 15-3562 Owner's Manual

Contents

Table 3. USB evolutionType Data Transfer Rate Category Introduction YearUSB 3.0 4.8 Gbps Super Speed 2010USB 2.0 480 Mbps High Speed 2000USB 1.1 12 Mbps Full Speed 1998USB 1.0 1.5 Mbps Low Speed 1996USB 3.0 (SuperSpeed USB)For years, the USB 2.0 has been firmly entrenched as the de facto interface standard in the PC world with about 6 billion devices sold, andyet the need for more speed grows by ever faster computing hardware and ever greater bandwidth demands. The USB 3.0 finally has theanswer to the consumers' demands with a theoretically 10 times faster than its predecessor. In a nutshell, USB 3.0 features are as follows:• Higher transfer rates (up to 4.8 Gbps)• Increased maximum bus power and increased device current draw to better accommodate power-hungry devices• New power management features• Full-duplex data transfers and support for new transfer types• Backward USB 2.0 compatibility• New connectors and cableThe topics below cover some of the most commonly asked questions regarding USB 3.0.SpeedCurrently, there are 3 speed modes defined by the latest USB 3.0 specification. They are Super-Speed, Hi-Speed and Full-Speed. The newSuperSpeed mode has a transfer rate of 4.8Gbps. While the specification retains Hi-Speed, and Full-Speed USB mode, commonly knownas USB 2.0 and 1.1 respectively, the slower modes still operate at 480Mbps and 12Mbps respectively and are kept to maintain backwardcompatibility.USB 3.0 achieves the much higher performance by the technical changes below:• An additional physical bus that is added in parallel with the existing USB 2.0 bus (refer to the picture below).• USB 2.0 previously had four wires (power, ground, and a pair for differential data); USB 3.0 adds four more for two pairs of differentialsignals (receive and transmit) for a combined total of eight connections in the connectors and cabling.• USB 3.0 utilizes the bidirectional data interface, rather than USB 2.0's half-duplex arrangement. This gives a 10-fold increase intheoretical bandwidth.54 Technology and components